Risk of cardiac rhythm disturbances and aortic regurgitation in different spondyloarthritis subtypes in comparison with general population: A register-based study from Sweden

Objectives To describe the incidence of atrioventricular (AV) block II-III, atrial fibrillation (AF), pacemaker implantation (PM) and aortic regurgitation in patients with ankylosing spondylitis (AS), undifferentiated spondyloarthritis (uSpA) and psoriatic arthritis (PsA) compared with the general population (GP) and with each other. Methods A prospective nationwide study with cohorts of patients with AS (n=6448), PsA (n=16 063) and uSpA (n=5190) and a GP (n=2 66 435) cohort, identified in 2001-2009 in the Swedish National Patient and Population registers. Follow-up began on 1 January 2006 and ended at event, death, emigration or 31 December 2012. Age-standardised and sex-standardised incidence rates and hazard ratios (HRs) were calculated. Results The highest incidence rates were noted for AF (5.5-7.4 events per 1000 person-years), followed by PM (1.0-2.0 events per 1000 person-years). HRs for AV block, AF, PM and aortic regurgitation were significantly increased in AS (HRs 2.3, 1.3, 2.1 and 1.9), uSpA (HRs 2.9, 1.3, 1.9 and 2.0) and PsA (HRs 1.5, 1.5, 1.6 and 1.8) compared with the GP cohort. The highest HRs were seen for AV block in male uSpA (HR 4.2) and AS (HR 2.5) compared with GP. Compared with PsA, significantly increased HRs were noted for PM (HR 1.5) in AS and for AV block (HR 1.8) in uSpA. Conclusions Patients with SpA are at increased risk of aortic regurgitation, cardiac rhythm disturbances and, as a probable consequence, also PM. Particularly for AF, the most common arrhythmia, increased caution is warranted, whereas AV block should be looked for especially in men with AS or uSpA.